


A naive T cell: The Unexpected Journey

by CogitoBUTnotSUM



Category: AU: Human Body, Original Work
Genre: Crack, One Shot, Pleasure House, Science What Science, Scientifically inaccurate for narrative purpose, but No Porn 'cause these cells don't fuck, immunology
Language: English
Status: Completed
Published: 2021-01-14
Updated: 2021-01-14
Packaged: 2021-03-18 13:34:35
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,105
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28744065
Author URL: https://archiveofourown.org/users/CogitoBUTnotSUM/pseuds/CogitoBUTnotSUM
Summary: This story is too short to have a summary.... but hopefully, it will make you smile...
Kudos: 1





	A naive T cell: The Unexpected Journey

**Author's Note:**

> This is the baby of a rainy Saturday night, my spouse out with friends, me at home with cosy pillows and a bottle of whisky (who needs a glass when you can drink straight from the bottle).
> 
> Enjoy!

Once upon a time there was a T cell. Specifically, a naive T cell busy enjoying freedom and the possibility to apply to any job in any part of the body. That was because, being naive, this T cell did not meet their right match yet, which would lead to their activation and maturation.

Now, the reader might ask, what the heck is the right match? To use an unusual metaphor, the right match for our T cell was like the biblical apple of knowledge. In the human body this apple was not offered by the evil snake but by devilish antigen presenting cells, like macrophages, dendritic cells or B cells (although some might argue that B cells were a bit undeserving to be included in this family). Anyway, only the right antigen presenting cell could share the right apple of knowledge that would make the right T cell glow like a morning sun, reaching activation and maturation.

Soon, that became the dream of our little T cell, tired of floating around without real purpose. Don’t get them wrong. They were happy, doing random jobs, meeting all those other cells in the stream that runs through the human body. But you know what they say, you cant just window shopping, at one point you have to enter and buy (correlation skills where art thou? Where did the author lose you?…). So, our naive T cell decided it was time to get activated.

And that was a problem. A big, big problem because of too many solutions.

There were many ways for the little cell to get activated and thus mature. Any organ had their own pool of antigen presenting cells, but did the little T cell really want to enter a tissue? Of course, the right antigen presenting cell carrying the right match could be there, but many scary stories were told about tissues. Sometimes those “tissue restricted” antigen presenting cells were real bitches. For example, you could find big dominant tissue resident macrophages there, one of the oldest antigen presenting cells in the human body. While our T cell was not sure if those cells were really scary or if that was but a legend, they were not that eager to find out. Yep, this naive T cell was a bit of a scared platelet (‘cause there are no cats in the body... just cute fluffy platelets...).

Fortunately, alternatives to tissues existed. The oldest and wisest T cells, aka the memory T cells, would often chant stories of the lymph nodes. Those were what we humans would call pleasure houses. There, a naive T cell would encounter mature macrophages or mature dendritic cells (because we will forget B cells, right?) And One of them could potentially be the right teacher to share the “apple to knowledge” and finally trigger the T cell activation, through an MHC-TCR contact (because these cells did not have hands but there were other ways to “touch” each other, if you know what I mean …) Anyway, that was a risky journey, toward the unknown. And not one, but many many nodes were dispersed in the body, so how could our little cell choose which node was the right one?

Follow the white stream and you will reach your dream, that was what old and wise T cells used to say.

The T cell did not have any idea what would be the best for them. But they were ready. No more random jobs, it was time to transition into a memory T cell and become a highly skilled player of the immune system. But being a little scared cell, our T cell decided to avoid tissues and started instead the long journey, ready to find some “activation action” in a node...

It was really a long journey. When the T cell took their final decision, they were somewhere in the foot region of the human body. And for some unknown reason (at least to the author), they decided that a cervical lymph node was where they would seek their activation partner. To truly understand the length of this unplanned journey, one should consider that our T cell was 7 micrometers (um) long. And the vessels to travel were, by underestimating approximation, 1,5 m long. If proportions are not an opinion and the math is not wrong, that’s slightly more than 360km for a human journey, if that human was 170cm tall (Ok scrap this, the author thought the journey was longer, something worth of Frodo! Not a trip from Glasgow to Liverpool...).

Anyway, where were we? Ah, the journey! It was not easy, but it was not lonesome either. Our T cell was quite an extrovert and truly appreciated good company. Of course, perils were behind every corner, or more specifically, behind every unexpected split of the blood vessels (you never know when a capillary might pop up…).

There were plenty of surface markers on the linen of those vessels. And what exactly are those? We humans might define surface markers as sticky tool (or handcuffs for those who like that...) used by pushy recruiters promising unskilled jobs and a chance, a weak one at that, of finding the right teacher required to trigger activation in the neighboring tissue. Our naive T cell was very careful in avoiding those sticky troubles! They were adamant in their desire! No more randomness! They were eager to specialize, eager to finally meet that big beautiful mature antigen presenting cell that would teach them the way. And when this would happen the T cell would stop being naive, fulfilling their destiny as a memory T cell.

Now, cells travel the human body much faster than trains, and in no time at all our T cell found the aimed node. But unfortunately, there was no matching teacher, no antigen presenting cell to activate the naive T cell. Thus, the node drained them, kicking them out of the lymphatic stream, back into the blood stream.

Fortunately, our little fighter did not give up. With hundreds and hundreds of nodes in the human body, they knew there was a suitable teacher out there! The T cell restarted the journey, seeking the right node where to find the right antigen presenting cell, to finally reach ~~nirvana~~ activation and turn into a memory T cell. Of course the universe is a bitch, and the journey took much longer than planned, turning into a lengthy and Frodo-worthy adventure. But the final destination was more than activation, it was a proof that our T cell was not a quitter and no journey could have ever made them bitter….

The End?

**Author's Note:**

> Dear reader, if you did not smile at least once while reading, I have failed. I'm sorry. My excuse? English is not my first language, writing academic papers is not a recommendable training to shape brilliant fiction-writing skills and when you are drunk everything is funnier...
> 
> I hope at least it made sense?.....=.=.......
> 
> ps. I now realizes how activationphopic is Nature, since an MHC-MHC or TCR-TCR activation would never occur...
> 
> As always, any type of feedback, positive/negative/neutral, is welcome!


End file.
